Nazzewski



Aug. 30, 1955 M. NAzzEwsKl GLOW LAMP Original Filed Feb. ll, 1953INVENToR. MATHEW NAZ ZEWSKI IS TTORNE/S United States Patent O GLow LAMPMathew Nazzewski, Adams, Mass., assiguor to Sprague Electric Company,North Adams, Mass., a corporation of Massachusetts Original No.2,695,970, dated November 30, 1954, Se-

rial No. 336,278, February 11, 1953. Application for reissue February10, 1955, Serial No. 487,481

3 Claims. (Cl. 313-117) Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue specification; matterprinted in italics indicates the additions made by reissue.

The present invention relates to a new and improved type of glow lamp.

A great many styles, size and shapes have been suggested for glow or aeolamps primarily used in recording sound upon a continuously moving stripof film. Light, to be used for this purpose must be directed upon thefilm in the form of extremely narrow, relatively short slits of uniformintensity throughout. Rather complicated lens systems have, in the past,been required to produce such light beams. Such systems, in addition tobeing expensive, suifer from inherent optical disadvantages. The priorart lamps used with such systems are, as a rule, characterized by lessresponse to voltage changes than are desired.

It is an object of the present invention to provide a glow or aeo lampswhich can be used in sound recording without an extremely complex lenssystem. A further object is to produce a lamp of the indicated categorywhich can be easily and cheaply manufactured, and which produces a slitof light of uniform intensity, and which is extremely sensitive tovoltage changes. These and other objects of the invention, as well asthe advantages of it, will be apparent from this description and claims,as the accompanying drawing, in which:

Figure l is a partially sectional front view of a glow lamp inaccordance with the invention; and

Figure 2 is a sectional view of the lamp of Figure l taken at line 2-2of Figure 1.

Briey, the glow lamp of the invention consists of two parallel flatsheet-like electrodes spaced close to one another and a slit-like shieldpositioned from said electrodes so as to restrict the light emitted fromthe area between them, the entire assembly being disposed in a sealedglass tube containing an ionizable gas such as neon,

. argon, or the like.

The invention will be best understood with reference to the accompanyingdrawings, especially Figure l. Here it is seen that the preferred lampof the invention consists of a glass envelope sealed at 11 so as tocontain an ionizable gas 21. The preferred gas for use with theinvention is argon, although other equivalent gas known to the art maybe used with satisfactory results. The gas 21 is retained within theenvelope 10 under pressure. In general, the higher the pressure the moresensitive the voltage response of the lamp. For optimum results basedupon practical and theoretical considerations it is presently consideredthat the pressure should be between about 2 and about 4 [atmospheres]millimeters.

The actual light emission results from the application or voltagebetween two ilat parallel electrodes 17. Each of these electrodes isplaced upon an insulating sheet 18 of mica or the like, and is held inposition by bent-over portions 19. By virtue of this construction theelectrodes 17 are free to expand in a crosswise direction when heatedWithout bulking. The bent-over portions 19 pref- Reissued Aug. 30, 1955erably extend for the length of the electrodes 17, and are positionedloosely within notches in the support members 18 so as to be able toexpand lengthwise. These electrodes 17 are attached as by soldering toleads 13 sealed within the envelopes 10 at 12.

The light emitted between the electrodes 17 is restricted in area to alarge extent by the spacing of these elements. In general, the distancebetween these electrodes 17 is from fg to M1 inch, although this is notcritical. This light is also restricted by two L-shaped members 15positioned so as to define a slit 16 extending substantially the lengthof the electrodes 17 and facing the space between these electrodes sothat light emitted from this area will pass through it. The L members 15are preferably formed of a dark metal so as to cut down the chances ofthe reection of unwanted radiation.

Both the L members 15 and the electrodes 17 can be positioned withrespect to one another by known means. One highly satisfactory methodcomprises attaching these elements to inert mica disks 14 by notching,these disks fitting closely within the walls of the envelope. In theparticular construction shown the wire leads 13 aid in holding theassembled members 14, 15, 17 and 18 in place.

Obviously, the glow lamp shown can be varied widely in construction.Instead of using separate shielding members 15 to deline a slit aunitary construction can be used for the same purpose, or theinside'walls of the glass envelope can be coated so as to define a slitfacing the electrodes. Rellective coatings or separate reflectors can beplaced opposed from the slit used so as to concentrate light upon thisslit, although such elements are not as a rule to be considerednecessary or desirable because they frequently tend to produce aslightly divergent emitted light beam.

The actual voltage used to generate this light, the amount with whichthe emitted beam is concentrated by a lens system which need onlyconsist of a single lens, as well as other factors aecting theconstruction and operation of the new glow lamp are items which are bestdetermined depending upon the specific application involved. Thoseskilled in the art will have a minimum of diticulty with suchdeterminations. For optimum results the slit employed should be placedin close proximity with the electrodes, and the width of the electrodesshould be at least ten times the Width of the slit. Further, this slitshould be at most 3/1 as wide as the distance between the electrodes foroptimum results.

As many apparently widely different embodiments of this invention may bemade without departing from the spirit and scope hereof, it is to beunderstood that the invention is not limited to the specific embodimentshereof except as defined in the appended claims.

What is claimed is:

1. A glow lamp comprising a sealed glass envelope, an ionizable gascontained within said envelope, insulating disk positioned within and atopposed ends of said envelope, two inert metal L-shaped memberssupported by said disk within said envelope, two parallel rectangularplate electrodes partially disposed between said L-shaped members andsupported by said disk, said insulating disk positioned perpendicular tothe axial planes of said electrodes and said member, said L-shapedmembers defining a focusing slit positioned parallel to said electrodesin such a manner that a plane parallel to said electrodes and disposedtherebetween will pass through said slit and wire leads extending fromsaid electrodes through said glass envelope.

2. A glow lamp comprising two parallel rectangular plate electrodes, twoinert metal L-shaped members disposed about said electrodes, saidmembers defining a slit uniplanar with the volume defined by anddisposed between said parallel electrodes, two electricallynon-conducting supporting disks positioned at the opposed ends of saidelectrodes and said members, a sealed glass envelope disposed about saidelectrode, said members and said disks, an ionizable gas containedwithin said envelope and wire leads extending from said electrodesthrough said envelope.

. 3. A glow lamp comprising two parallel rectangular plate electrodes, asealed glass envelope disposed about said electrodes, electricallynon-conducting supports for 10 said electrodes within said envelope, anionizable gas contained within said envelope, wire leads extending fromsaid electrodes through said envelope, and opaque means within saidenvelope constructed and arranged to substantially encompass saidelectrodes but defining a slit uniplanar with the volume dened by anddisposed between said parallel electrodes.

References Cited in the le of this patent or the original patent UNITEDSTATES PATENTS 1,850,467 Nakken Mar. 22, 1932 1,864,547 Morton et alJune 28, 1932 1,879,472 Pirani Sept. 27, 1932 2,111,231 Von ArndenneMar. 1S, 1938

